DESCRIPTION: The feasibility of a new technique for light control in scintillation cameras will be tested. The method is applicable to any type of solid scintillator and can narrow the intrinsic spreading of light significantly thereby allowing improved spatial resolution. Furthermore, it will be possible to deterministically tailor the light spread function to have desirable properties. The technique is suitable for any Anger camera--especially those employing thick scintillators. In particular, spatial resolution for low- energy imaging can be retained for a crystal thick enough to have good detection efficiency at 511 keV. The Phase I effort will evaluate feasibility for both CsI and NaI scintillators and will develop light-control parameters for a thick-crystal camera.